Year	Number of
1990	84.28
1991	85.12
1992	86.63
1993	88.57
1994	92.07
1995	97.92
1996	104.2
1997	112.32
1998	123.34
1999	133.9
2000	145.38
2001	152.36
2002	157.99
2003	158.94
2004	154.66
2005	144.6
2006	138.39
2007	134.63
2008	132.8
2009	128.07
2010	126.6
2011	126.87
2012	133.06
2013	134.66
2014	139.74
2015	145.83
2016	152.59
